# Maintainer: Natanael Copa <ncopa@alpinelinux.org>

_flavor=spacemit
pkgname=linux-$_flavor
pkgver=6.6.53
_kernver=${pkgver%.*}
pkgrel=0
pkgdesc="Linux lts kernel"
url="https://www.kernel.org"
depends="initramfs-generator"
_depends_dev="perl gmp-dev mpc1-dev mpfr-dev elfutils-dev bash flex bison zstd"
makedepends="$_depends_dev sed installkernel bc linux-headers linux-firmware-any openssl-dev>3 mawk
	u-boot-tools diffutils findutils zstd pahole python3 gcc>=13.1.1_git20230624"
options="!strip !check"
_config=${config:-config-lts.${CARCH}}

# sources are based on:
# https://gitee.com/bianbu-linux/linux-6.6.git
# The upstream source tree appears to be based on a fresh v6.6.36 checkin and
# then a few huge commits on top of that. A proper branch was pushed to
# spacemit-6.6.y branch on https://github.com/ncopa/linux.git
#
# Finally 6.6.52 was merged into that branch and conflicts resolved, and
# branched as spacemit-6.6.52-alpine and a diff uploaded to dev.a.o
#
source="https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/linux-$_kernver.tar.xz
	https://dev.alpinelinux.org/archive/spacemit-patches/spacemit-$pkgver-alpine.patch

	0003-kexec-add-kexec_load_disabled-boot-option.patch
	0004-objtool-respect-AWK-setting.patch

	001-device-tree-overlay-support.patch
	004-Add-board-BananaPi-F3.patch
	005-Bluetooth-Add-support-for-RTL8852BS.patch
	006-rtl8852bs-Turn-off-DEBUG-and-remove-RTW_WARN_LM.patch

	spacemit.riscv64.config
	"
subpackages="$pkgname-dev:_dev:$CBUILD_ARCH $pkgname-doc"
for _i in $source; do
	case $_i in
	*.$CARCH.config)
		_f=${_i%."$CARCH".config}
		_flavors="$_flavors $_f"
		if [ "linux-$_f" != "$pkgname" ]; then
			subpackages="$subpackages linux-$_f::$CBUILD_ARCH linux-$_f-dev:_dev:$CBUILD_ARCH"
		fi
		;;
	esac
done
builddir="$srcdir"/linux-$_kernver

if [ "${pkgver%.0}" = "$pkgver" ]; then
	# Prepend to apply first
	source="patch-$pkgver.patch.xz::https://cdn.kernel.org/pub/linux/kernel/v${pkgver%%.*}.x/patch-$pkgver.xz $source"
fi
arch="riscv64"
license="GPL-2.0-only"

# secfixes:
#   5.10.4-r0:
#     - CVE-2020-29568
#     - CVE-2020-29569
#   5.15.74-r0:
#     - CVE-2022-41674
#     - CVE-2022-42719
#     - CVE-2022-42720
#     - CVE-2022-42721
#     - CVE-2022-42722
#   6.1.27-r3:
#     - CVE-2023-32233
#   6.6.13-r1:
#     - CVE-46838

prepare() {
	default_prepare

	# remove localversion from patch if any
	rm -f localversion*
}

_kernelarch() {
	local arch="$1"
	case "$arch" in
		aarch64*) arch="arm64" ;;
		arm*) arch="arm" ;;
		ppc*) arch="powerpc" ;;
		s390*) arch="s390" ;;
		riscv*) arch="riscv" ;;
		loongarch64) arch="loongarch" ;;
	esac
	echo "$arch"
}

_prepareconfig() {
	local _flavor="$1"
	local _arch="$2"
	local _config=$_flavor.$_arch.config
	local _builddir="$srcdir"/build-$_flavor.$_arch
	mkdir -p "$_builddir"
	echo "-$pkgrel-$_flavor" > "$_builddir"/localversion-alpine

	cp "$srcdir"/$_config "$_builddir"/.config
	msg "Configuring $_flavor kernel ($_arch)"
	make -C "$builddir" \
		O="$_builddir" \
		ARCH="$(_kernelarch $_arch)" \
		olddefconfig

	if grep "CONFIG_MODULE_SIG=y" "$_builddir"/.config >/dev/null; then
		if [ -f "$KERNEL_SIGNING_KEY" ]; then
			sed -i -e "s:^CONFIG_MODULE_SIG_KEY=.*:CONFIG_MODULE_SIG_KEY=\"$KERNEL_SIGNING_KEY\":" \
				"$_builddir"/.config
			msg "Using $KERNEL_SIGNING_KEY to sign $_flavor kernel ($_arch) modules"
		else
			warning "KERNEL_SIGNING_KEY was not set. A signing key will be generated, but 3rd"
			warning "party modules can not be signed"
		fi
	fi
}

listconfigs() {
	for i in $source; do
		case "$i" in
			*.config) echo $i;;
		esac
	done
}

prepareconfigs() {
	for _config in $(listconfigs); do
		local _flavor=${_config%%.*}
		local _arch=${_config%.config}
		_arch=${_arch#*.}
		local _builddir="$srcdir"/build-$_flavor.$_arch
		_prepareconfig "$_flavor" "$_arch"
	done
}

# this is supposed to be run before version is bumped so we can compare
# what new kernel config knobs are introduced
prepareupdate() {
	clean && fetch && unpack && prepare && deps
	prepareconfigs
	rm -r "$builddir"
}

updateconfigs() {
	if ! [ -d "$builddir" ]; then
		deps && fetch && unpack && prepare
	fi
	for _config in ${CONFIGS:-$(listconfigs)}; do
		msg "updating $_config"
		local _flavor=${_config%%.*}
		local _arch=${_config%.config}
		_arch=${_arch#*.}
		local _builddir="$srcdir"/build-$_flavor.$_arch
		mkdir -p "$_builddir"
		echo "-$pkgrel-$_flavor" > "$_builddir"/localversion-alpine
		local actions="listnewconfig oldconfig"
		if ! [ -f "$_builddir"/.config ]; then
			cp "$srcdir"/$_config "$_builddir"/.config
			actions="olddefconfig"
		fi
		env | grep ^CONFIG_ >> "$_builddir"/.config || true
		make -j1 -C "$builddir" \
			O="$_builddir" \
			ARCH="$(_kernelarch $_arch)" \
			$actions savedefconfig

		cp "$_builddir"/defconfig "$startdir"/$_config
	done
}

set_kbuild_timestamp() {
	# KBUILD_BUILD_TIMESTAMP needs to be parsable by busybox date
	export KBUILD_BUILD_TIMESTAMP="$(date '+%Y-%m-%d %H:%M:%S' -u${SOURCE_DATE_EPOCH:+d @$SOURCE_DATE_EPOCH})"
}

build() {
	unset LDFLAGS
	# for some reason these sometimes leak into the kernel build,
	# -Werror=format-security breaks some stuff
	unset CFLAGS CPPFLAGS CXXFLAGS
	set_kbuild_timestamp
	for i in $_flavors; do
		_prepareconfig "$i" "$CARCH"
	done
	for i in $_flavors; do
		msg "Building $i kernel"
		cd "$srcdir"/build-$i.$CARCH

		# set org in cert for modules signing
		# https://www.kernel.org/doc/html/v6.1/admin-guide/module-signing.html#generating-signing-keys
		mkdir -p certs
		sed -e 's/#O = Unspecified company/O = alpinelinux.org/' \
			"$builddir"/certs/default_x509.genkey \
			> certs/x509.genkey

		make ARCH="$(_kernelarch $CARCH)" \
			DTC_FLAGS="-@" \
			CC="${CC:-gcc}" \
			AWK="${AWK:-mawk}" \
			KBUILD_BUILD_VERSION="$((pkgrel + 1 ))-Alpine"
	done
}

_package() {
	local _buildflavor="$1" _outdir="$2"
	set_kbuild_timestamp

	cd "$srcdir"/build-$_buildflavor.$CARCH
	local _abi_release="$(make -s kernelrelease)"
	# modules_install seems to regenerate a defect Modules.symvers on s390x. Work
	# around it by backing it up and restore it after modules_install
	cp Module.symvers Module.symvers.backup

	mkdir -p "$_outdir"/boot "$_outdir"/lib/modules

	local _install
	case "$CARCH" in
		arm*|aarch64) _install="zinstall dtbs_install";;
		riscv*) _install="install dtbs_install";;
		*) _install=install;;
	esac

	make modules_install $_install \
		ARCH="$(_kernelarch $CARCH)" \
		INSTALL_MOD_PATH="$_outdir" \
		INSTALL_MOD_STRIP=1 \
		INSTALL_PATH="$_outdir"/boot \
		INSTALL_DTBS_PATH="$_outdir/boot/dtbs-$_buildflavor"

	cp Module.symvers.backup Module.symvers

	rm -f "$_outdir"/lib/modules/"$_abi_release"/build \
		"$_outdir"/lib/modules/"$_abi_release"/source
	rm -rf "$_outdir"/lib/firmware

	install -D -m644 include/config/kernel.release \
		"$_outdir"/usr/share/kernel/$_buildflavor/kernel.release

	case "$CARCH" in
	loongarch64)
		mv  "$_outdir"/boot/vmlinuz-$_abi_release \
			"$_outdir"/boot/vmlinuz-$_buildflavor

		mv  "$_outdir"/boot/config-$_abi_release \
			"$_outdir"/boot/config-$_buildflavor

		mv  "$_outdir"/boot/System.map-$_abi_release \
			"$_outdir"/boot/System.map-$_buildflavor
		;;
	esac
}

# main flavor installs in $pkgdir
package() {
	depends="$depends linux-firmware-any"

	_package "$_flavor" "$pkgdir"

	# copy files for linux-lts-doc sub package
	mkdir -p "$pkgdir"/usr/share/doc
	cp -r "$builddir"/Documentation \
		"$pkgdir"/usr/share/doc/linux-doc-"$pkgver"/
	# remove files that aren't part of the documentation itself
	for nondoc in \
		.gitignore conf.py docutils.conf \
		dontdiff Kconfig Makefile
	do
		rm "$pkgdir"/usr/share/doc/linux-doc-"$pkgver"/"$nondoc"
	done
	# create /usr/share/doc/linux-doc symlink
	cd "$pkgdir"/usr/share/doc; ln -s linux-doc-"$pkgver" linux-doc
}

# subflavors install in $subpkgdir
virt() {
	_package virt "$subpkgdir"
}

_dev() {
	local _flavor=$(echo $subpkgname | sed -E 's/(^linux-|-dev$)//g')
	local _builddir="$srcdir"/build-$_flavor.$CARCH
	local _abi_release="$(make -C "$_builddir" -s kernelrelease)"
	# copy the only the parts that we really need for build 3rd party
	# kernel modules and install those as /usr/src/linux-headers,
	# simlar to what ubuntu does
	#
	# this way you dont need to install the 300-400 kernel sources to
	# build a tiny kernel module
	#
	pkgdesc="Headers and script for third party modules for $_flavor kernel"
	depends="$_depends_dev"
	local dir="$subpkgdir"/usr/src/linux-headers-"$_abi_release"
	set_kbuild_timestamp

	# first we import config, run prepare to set up for building
	# external modules, and create the scripts
	mkdir -p "$dir"
	cp -a "$_builddir"/.config "$_builddir"/localversion-alpine \
		"$dir"/

	install -D -t "$dir"/certs "$_builddir"/certs/signing_key.x509 || :

	make -C "$builddir" \
		O="$dir" \
		ARCH="$(_kernelarch $CARCH)" \
		AWK="${AWK:-mawk}" \
		prepare modules_prepare scripts

	# remove the stuff that points to real sources. we want 3rd party
	# modules to believe this is the sources
	rm "$dir"/Makefile "$dir"/source

	# copy the needed stuff from real sources
	#
	# this is taken from ubuntu kernel build script
	# http://kernel.ubuntu.com/git/ubuntu/ubuntu-zesty.git/tree/debian/rules.d/3-binary-indep.mk
	cd "$builddir"
	find .  -path './include/*' -prune \
		-o -path './scripts/*' -prune -o -type f \
		\( -name 'Makefile*' -o -name 'Kconfig*' -o -name 'Kbuild*' -o \
		   -name '*.sh' -o -name '*.pl' -o -name '*.lds' -o -name 'Platform' \) \
		-print | cpio -pdm "$dir"

	cp -a scripts include "$dir"

	find "arch/$_karch" -name include -type d -print | while IFS='' read -r folder; do
		find "$folder" -type f
	done | sort -u | cpio -pdm "$dir"

	install -Dm644 "$srcdir"/build-$_flavor.$CARCH/Module.symvers \
		"$dir"/Module.symvers

	# remove unneeded things
	msg "Removing documentation..."
	rm -r "$dir"/Documentation
	find "$dir" -type f -name '*.o' -printf 'Removing %P\n' -delete
	local _karch="$(_kernelarch $CARCH | sed 's/x86_64/x86/')"
	msg "Removing unneeded arch headers..."
	for i in "$dir"/arch/*; do
		if [ "${i##*/}" != "$_karch" ]; then
			echo "  ${i##*/}"
			rm -r "$i"
		fi
	done

	mkdir -p "$subpkgdir"/lib/modules/"$_abi_release"
	ln -sf /usr/src/linux-headers-"$_abi_release" \
		"$subpkgdir"/lib/modules/"$_abi_release"/build
}

sha512sums="
5ba9f43e95e2ac534fa74d66a00e19112473eed8ed6293171621662b9e3b5d2c4b42d9b2d6d6700e388747431eab5e358572c3222ad7a7eae316c9e997818d26  patch-6.6.53.patch.xz
458b2c34d46206f9b4ccbac54cc57aeca1eaecaf831bc441e59701bac6eadffc17f6ce24af6eadd0454964e843186539ac0d63295ad2cc32d112b60360c39a35  linux-6.6.tar.xz
d93f98f70bf97fe5f3cbb5992c6a058fb954c43d5933329bf6b49f3ea59fdc22289c6c60203b95a4c27ed70064019eeba49f6cefdaed34b57a787a7dd745ff47  spacemit-6.6.53-alpine.patch
75f232b6becee7d36d360ffaf2aaa837d13518f9ec620ca159bcb2a0e98eb18a77631406a9b44244ea0164a7ed59fad583823909681e9b894a012f9d13365b69  0003-kexec-add-kexec_load_disabled-boot-option.patch
2956050bb332411d00a285e9656618f2e34b631492bbc19bef54d83a6e91b8531f4e18830b9313cfe52fbf8a8ca6fb76cf55b3ddd146ca3b977046cf2fd10cad  0004-objtool-respect-AWK-setting.patch
700a54bd82ea63386871b6e9c4695de57ccfa1500d440586ab8374569f1f4ad5a68827358798805cfa6cab591da06d6c0c5d91031db4c1832da549629d6dc8d4  001-device-tree-overlay-support.patch
9b63b181ddb719b07f1a65d6bdd19c5d4d11dc4d9f6f638d05435c826e4ffb7790cc0b6158f8c8598c01bb66118bb241b0e0d472240c6767d7a3d1b11a90e214  004-Add-board-BananaPi-F3.patch
d025a943f6315fd36dc6db1894ab2e76e488bb01427ee3a94fd6a8451a3478bd17ebed904c93bf134c2d9da88db9da037014b8e954d1a8f695336c63fe6ba49b  005-Bluetooth-Add-support-for-RTL8852BS.patch
66a2482abd33f16eceeb120e48829564941ed9e5274ea6395602707c55e72f08cbc9dc0fe7ef303348abb4a7f810553ca498fe127683a41ba9a19fe442fcaccd  006-rtl8852bs-Turn-off-DEBUG-and-remove-RTW_WARN_LM.patch
70a8d3b95c6adaed95689e5d1d59e40d8c427558d6e31a7ca9153692bea79cb616c94312d028674ce438e0ebf14fcbe63bbc27f5b1505e72e3823d7ae459a6df  spacemit.riscv64.config
"
